Process for making imidazolinium salts, fabric conditioning compositions and methods

ABSTRACT

A process for making quaternary imidazolinium fabric conditioning agents essentially free of amines, amine salts and alkoxylated forms of the quaternary imidazolinium salts. An aqueous liquid fabric conditioning composition containing quaternary imidazolinium conditioning agents essentially free of amines and amine salts possesses desirable stability and conditioning properties.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of application Ser. No.687,951, entitled "Process for Making Imidazolinium Salts, FabricConditioning Compositions and Methods," filed May 20, 1976, nowabandoned.

BACKGROUND OF THE INVENTION

This invention relates to the production of quaternary imidazoliniumfabric conditioning agents essentially free of amines, amine salts andalkoxylated forms of the quaternary imidazolinium salts. The presentinvention additionally relates to a fabric conditioning compositioncontaining an imidazolinium agent essentially free of amines and aminesalts and a method for conditioning fabrics.

In the conventional home laundering process, soiled fabrics aresubjected to cleaning with a detergent composition in the main washcycle and rinsing with water in the final cycle. Optionally, during therinsing cycle a fabric conditioning composition is added. Suchcompositions contain a fabric softener or fabric antistat material forimparting to the rinsed fabrics softening and antistat properties. Therinsed fabrics are oftentimes, thereafter, dried in an automatic clothesdryer.

Many different types of fabric conditioning agents have been used inrinse cycle added fabric conditioning compositions. The most favoredtype of agent has been the quaternary ammonium compounds. Thesecompounds may take the form of noncyclic quaternary ammonium saltshaving preferably two long chain alkyl groups attached to the nitrogenatom. Additionally, imidazolinium salts have been used by themselves orin combination with other agents in the treatment of fabrics. U.S. Pat.No. 2,874,074, Feb. 17, 1959, to Johnson discloses using imidazoliniumsalts to condition fabrics. U.S. Pat. No. 3,681,241, Aug. 1, 1972, toRudy, and U.S. Pat. No. 3,033,704, May 8, 1962, to Sherrill et al.disclose fabric conditioning compositions containing mixtures ofimidazolinium salts and other fabric conditioning agents.

While the prior art shows the use of quaternary imidazolinium salts asfabric conditioning agents, it is silent about the problems encounteredin making stable fabric conditioning compositions containing such agentsand aldehydes. The manufacture of imidazolinium salts generally involvesthe reaction of a polyamine with an acyl containing material such as anacid or ester to form an imidazoline and then a quaternizing of theimidazoline. U.S. Pat. Nos. 2,355,837, Aug. 15, 1944, and 2,267,965,Dec. 30, 1941, to Wilson; and U.S. Pat. No. 2,520,102, Aug. 22, 1950, toTryon, all disclose methods for making imidazolines used in makingimidazolinium salts. It has been found in the present invention that inaddition to the imidazoline compound formed in the described reaction,primary and secondary amines are also present. During the subsequentquaternization step, these amines cause some of the imidazoline compoundto form the imidazoline amine salt rather than the quaternaryimidazolinium salt. The imidazoline amine salt, when present in anaqueous medium having a near neutral or higher pH, is capable ofundergoing ring opening to form free amines which will then react withaldehydic compounds in the composition much the same as free amineswhich have not been converted to the salt form. The result is that theodor of the composition degrades (perfumes generally contain aldehydes),the color and the pH change and aldehyde preservatives degrade. Theaforementioned Johnson patent describes making quaternary imidazoliniumsalts, but is silent about how to overcome the problems described whilestill achieving an end product which is sufficiently high inimidazolinium salt to be commercially attractive. In the process aspectof the present invention the undesirable amines are "capped" using analkoxylating agent in an amount sufficient to cap the primary andsecondary amines but not cap to any appreciable degree the cyclictertiary amine which forms the imidazolinium salt.

It is, therefore, an object of this invention to provide a process formaking quaternary imidazolinium salts which are essentially free ofamines, amine salts and alkoxylated forms of the imidazolinium salts.

It is another object of this invention to provide a fabric conditioningcomposition comprising a quaternary imidazolinium salt and beingessentially free of amines and amine salts.

It is still another object of this invention to provide a method forconditioning fabrics by treating them with the desired imidazoliniumsalts.

These and other objects will become apparent from the description whichfollows.

As used herein all percentages and ratios are by weight unless otherwisespecified.

SUMMARY OF THE INVENTION

The present invention encompasses in one aspect a process for makingimidazolinium salts having the following formula: ##STR1## wherein R andR₁ are aliphatic or cycloaliphatic hydrocarbon groups containing fromabout 10 to about 22 carbon atoms; D is a divalent nonamino organicradical containing from about 1 to about 20 carbon atoms and is composedof elements selected from the group consisting of C, O, N and H. X is ananion; R₂ is an alkyl, substituted alkyl or aralkyl group containingfrom about 1 to about 8 carbon atoms. R₃ and R₄ hydrogen, hydroxy, ashort chain alkyl having from 1 to 4 carbon atoms or hydroxy forms ofthe short chain alkyl. In an optional form D may be absent and R₁attached directly to the number 1 nitrogen in the ring. In anotheroption, R₁ and D may be absent and in their place a group from theimidazoline forming amine may be present. The imidazolinium salts areessentially free of amines, amine salts and alkoxylated forms of theimidazolinium salts. It is to be appreciated that while the R₂ group isshown as being on the number 3 nitrogen, it may also be present on thenumber 1 nitrogen.

The invention also encompasses a fabric conditioning compositioncomprising a quaternary imidazolinium salt which is essentially free ofamines and amine salts. Methods of conditioning fabrics with theimidazolinium salts are also provided.

DETAILED DESCRIPTION OF THE INVENTION

In accordance with this invention, quaternary imidazolinium saltsessentially free of amines, amine salts and alkoxylated forms of theimidazolinium salts are produced.

The reaction to form the desired imidazolinium salt involves thefollowing steps:

FORMATION OF IMIDAZOLINE

The imidazoline precursor for the desired imidazolinium salt is formedby reacting acylating or esterifying agents with alkylene orpolyalkylene polyamines having two or three amino groups, one of whichis a primary or secondary amino group in the 2 position to a primaryamino group. The reaction is conducted at a temperature of about 100° C.to about 250° C. for a period of about 3 to about 24 hours, at a molarratio of acyl groups to primary amine and hydroxyl groups ranging fromabout 0.33:1 to about 1.5:1, preferably from about 1:1 to about 1.5:1,and under reflux or at atmospheric pressure or slightly greater. Tofacilitate the formation of the imidazoline ring structure the reactionmixture may subsequently be subjected to a vacuum of from about 0.4 toabout 10 mm of mercury for a period of from about 1 to about 8 hours.The resulting mixture contains in addition to the desired imidazolinesome of the original acylating material, some of the original polyamine,some of the noncyclized intermediate amide products and other mixedreaction products. The acylating or esterifying agent may be any acid orother acyl containing compound having an aliphatic or cycloaliphatichydrocarbon group of about 10-22 carbon atoms. Examples of suchmaterials include the fatty acids lauric, decanoic, undecanoic,dodecanoic, tridecanoic, myristic, pentadecanoic, hexadecanoic, palmiticand the like. Preferred fatty acids are the mixtures thereof derivedfrom tallow, soybean or coconut oils. Particularly preferred are thesoft or hardened tallow fatty acids. Other acylating or esterifyingagents include the alkyl esters of the fatty acids and the naturallyoccurring glyceride esters. The latter are preferred for use herein.

The polyamine material, as indicated above, has either two or threeamino groups wherein one is a primary or secondary amino group in the 2position to a primary amine group. These preferably take the followingform:

    NH.sub.2 --CH.sub.2 --CH.sub.2 --NH--X

where X may be, for example, hydrogen, --CH₂ --CH₂ --_(n) --NH₂ , --CH₂--CH₂ --_(n) --OH or --CH₂ --CH₂ --_(n) --CH₃ wherein n is from 1 toabout 6. Examples of such polyamines include diethylenetriamine,ethylenediamine, hydroxyethyl ethylenediamine, etc.

Addition of Second Long Chan Alkyl or Substituted Alkyl Group

As described above, the formation of the imidazoline is accomplished byreacting a polyamine with an acylating or esterifying agent. If theamount of acylating or esterifying agent used is not sufficient to forman amide or ester with at least two of the amine or hydroxyl groupspresent in the polyamine (the molar ratio of acyl groups to primaryamine or hydroxyl groups being from about 0.33 to about 0.66), theimidazoline formed will only have a long chain group of the type desiredpositioned at the 2 position rather than at both the 1 and 2 positionsof the imidazoline ring. The mono substituted material then has to bereacted further with an acylating or esterifying agent. The reactiontemperature is generally the same as the generalized reaction givenabove while the molar ratio of acylating agent or esterifying agent tomono substituted imidazoline ranges from about 1:1 to about 1.5:1 andthe reaction time ranges from about 1 to about 24 hours. Optionally, avacuum of from about 0.4 to about 10 mm of mercury is drawn. Thisreaction can be exemplified as follows using diethylenetriamine as thepolyalkylene polyamine: ##STR2## where R is an aliphatic orcycloaliphatic hydrocarbon group containing from about 10 to about 22carbon atoms.

The primary amine present in the imidazoline formed above then has to beconverted to an amide to attach the second long chain R group in thefollowing manner: ##STR3## where R₁ is an aliphatic or cycloaliphatichydrocarbon group containing from about 10 to about 22 carbon atoms. Thegroup ##STR4## in the above formula corresponds to D in the formulagiven above in the Summary of the Invention section. It should beappreciated that D may be another divalent radical or absent dependingon the choice and concentration of polyamine and acylating oresterifying agent. See, for example, U.S. Pat. 2,267,965 to Wilson,mentioned previously, where an hydroxy group is attached to the 1position of the imidazoline ring. Also the other U.S. Patent to Wilsonmentioned previously, U.S. Pat. No. 2,355,837, for other polyamines.

Of course, if the amount of acylating or esterifying agent used containsa number of acylating groups sufficient to form an amide or ester withat least two of the amine or hydroxyl groups (ratio of acyl to primaryamine or hydroxyl groups is from about 0.67 to about 1.5:1, preferably1:1 to about 1.1:1), the long chain group in the 1 position would bepresent as a result of the initial imidazoline forming reaction. Thefollowing represents such a reaction: ##STR5## Some of the startingintermediate amides shown above, as well as some of the startingmaterials, other intermediates, water and other complexes are present asdiluents along with the desired substituted imidazoline. Some of thediluents are removed during the vacuum stage of the reaction.

Alkoxylation of Imidazoline

The formation of the 1,2 substituted imidazoline product will have ascomponents in addition to the desired imidazoline product the materialsnoted as diluents in the glyceride reaction above. If the imidazolinereaction formation is the fatty acid reaction given above wherein the 2substituted imidazoline is formed first and then the second long chainaliphatic or cycloaliphatic hydrocarbon group is added in the 1 positionby means of a reaction with a fatty acid, or other agent, the desiredimidazoline is going to be present in a mixture containing some of theimidazoline substituted only at the 2 position and fatty acid or otheragent. Similarly, regardless of which reaction route is used, there willbe primary and/or secondary amines present in the final mixture due toeither unreacted initial amine or the amide intermediate products. Thematerials which have primary and secondary amine groups present areundesirable since in the quaternizing step, to be discussedsubsequently, the amines cause the disubstituted imidazoline to betransformed to an amine salt rather than a quaternary salt which, inturn, is capable of reverting to free amines when present in an aqueouscomposition having a pH of about 5 or greater. The patent issued toJohnson, U.S. Pat. No. 2,874,074, Feb. 17, 1959, mentioned earlier inthis application, discloses making the 1,2 substituted imidazoline bythe two step fatty acid process. Johnson utilizes the 2 substitutedimidazoline as made by Wilson, U.S. Pat. Nos. 2,355,837, Aug. 15, 1944,or 2,267,965, Dec. 30, 1941. The imidazoline product as made by Johnsonwould contain a mixture of the 1,2 substituted material, the 2substituted material, other amine containing materials and fatty acid.The 2 substituted material and the other amines are undesirable, asindicated above, due to their ability to cause the imidazoline salt tobe formed.

The present applicants have found that the undesirable amine productspresent in the 1,2 substituted imidazoline reaction mixture can beeffectively capped by treating the mixture with an alkylene oxide,preferably propylene oxide. The alkylene oxide serves to "cap" theamines by attaching an alkylene oxide moiety to the free amine. It isimportant that all of the primary and secondary amines are capped, butonly a minimum of tertiary amine in the imidazoline. To achieve thesegoals the mixture containing the desired 1,2 substituted imidazoline istreated with an amount of an alkylene oxide amounting to from about 1 to5% by weight of the mixture to be treated, while the temperature is keptat from about 80° C. to about 140° C. and a vacuum is optionally drawnamounting to from about 2 to about 15 mm. mercury. The vacuum helps torid the system of excess alkylene oxide, polyamine and other low boilingdiluents. The imidazoline containing mixture can also be diluted with anorganic solvent such as isopropyl alcohol or glymes to facilitate thealkylene oxide treatment. Such solvents are used in an amount of fromabout 1 to about 25% by weight of the imidazoline mixture. The time ofthe reaction ranges from about 0.5 to about 8 hours. U.S. Pat. No.2,713,582, July 19, 1955, to Smith, discloses making fully alkoxylatedimidazolines as a precursor for carboxylate detergent products. Examplesof alkoxylating agents other than propylene oxide include butyleneoxide, glycide, ethylene oxide, cyclohexame oxide, etc.

Quaternization

The alkylene oxide treated mixture from above is treated with analkylating agent to form the desired quaternary imidazolinium materialessentially free of amines, amine salts and alkoxylated forms of theimidazolinium salts. The imidazolinium product preferably contains atotal less than about 4%, preferably less than about 2%, of primaryamines, secondary amines and cyclic tertiary amine salts and less thanabout 25%, preferably 4%, of the alkoxylated form of the imidazoliniumsalt. The limit on the alkoxylated form is the result of wanting to makethe nonalkoxylated imidazolinium salt as pure as possible and is notrelated to the amine/amine salt stability problem. The alkylating agentcan be any of the known agents such as methylchloride, ethylbromide,diethylsulfate, dimethylsulfate, hexadecylchloride, among many others.The reaction can be exemplified in the following manner: ##STR6##wherein D, R, R₁, R₃ and R₄ are as described previously.

The amount of alkylating agent used should be equivalent to the amountof the imidazoline treated on a molar basis. However, an excess of thealkylating agent is generally used to assure maximum quaternization. Theamount of excess employed should be sufficient so that the pH of thereaction medium is in the range of from about 5 to about 7. The reactiontime generally ranges from about 1 to about 12 hours and the temperaturefrom about 40° to about 80° C. If desired, a base may be added duringthe alkylation to aid quaternization.

The imidazolinium salt as formed above has outstanding fabricconditioning properties, softening and antistatic, while additionallyallowing fabric conditioning compositions to be made which have improvedaldehyde stability. A preferred imidazolinium salt contains R₁ and Rgroups having 14-20 carbon atoms such as the following wherein the Rgroups are tallow cuts: ##STR7## wherein C_(Tallow) is an aliphatichydrocarbon chain derived from tallow fatty acid.

Other quaternary imidazolinium salts having desirable properties can beformed by substituting a different R group for tallow in the acylatingor esterifying agent, a different alkylene or polyalkylene polyamine fordiethylenetriamine, and a different alkyl, substituted alkyl or aralkylfor the methyl group present, as well as a different anion, in thealkylating agent.

FABRIC CONDITIONING COMPOSITIONS

The present invention is also directed to compositions comprising 1,2substituted quaternary imidazolinium salts, said compositions containinga total less than about 4%, preferably less than about 2%, of primaryamines, secondary amines and cyclic tertiary amine salts based on theweight of the imidazolinium salt. Additionally, the compositionspreferably contain less than about 25%, more preferably less than about4%, of the alkoxylated form of the imidazolinium salt based on theweight of the nonalkoxylated form of the imidazolinium salt. The desiredimidazolinium salt can be prepared using the process previouslydescribed, or another process which will yield the imidazolinium saltand will not have more than the above indicated levels of the variousundesirable compounds. As indicated earlier, the imidazolinium compoundsof interest herein have the formula: ##STR8## wherein D is a nonaminodivalent organic radical containing from 1 to about 20 carbon atomscomprised of elements selected from C, H, N and O. R and R₁ arealiphatic or cycloaliphatic hydrocarbon groups having from about 10 toabout 22 carbon atoms. R₃ and R₄ are hydrogen, hydroxyl, short chainalkyl having from 1 to 4 carbon atoms or hydroxy forms of the shortchain alkyl. Examples of D are ##STR9## among many others. where n is anumber from 1 to about 6. R₂ is an alkyl, substituted alkyl or aralkylhaving from about 1 to 8 carbon atoms, which was associated with thealkylating agent used to quaternize the imidazoline compound. Examplesof such cations are methyl, ethyl, benzyl, etc. X is an anion associatedwith the alkylating agent and may be, for example, chloride, bromide,methylsulfate, ethylsulfate, among others. It is to be recognized thatwhile the quaternization is indicated as having taken place at3-nitrogen, quaternization at the 1-nitrogen atom is not excluded. Apreferred quaternary imidazolinium salt is the methylsulfate salt shownabove.

The compositions of the present invention are preferably aqueous and maycontain any desired level of the quaternary imidazolinium salt. However,the compositions preferably contain from about 1 to about 15% of thesalt and most preferably from about 2 to about 8%.

In addition to the preferred quaternary imidazolinium salt, thecompositions of the present invention may also contain other fabricconditioning (softening/antistatic) agents. Such other agents may bedescribed as cationic or nonionic organic materials which are free ofprimary amines, secondary amines and cyclic tertiary amine salts and aregenerally employed as fabric conditioning agents during the rinsingcycle of the household laundering process. They are organic, waxymaterials having a melting (or softening) point between 25° C. and 115°C. Such materials possess both fabric softening and fabric antistatproperties.

Generally the cationic nitrogen-containing compounds such as quaternaryammonium compounds have one or two straight-chain organic groups of atleast eight carbon atoms. Preferably, they have one or two such groupsof from 12 to 22 carbon atoms. Preferred cation-active softenercompounds include the quaternary ammonium antistat/softener compoundscorresponding to the formula: ##STR10## wherein R₁ is hydrogen or analiphatic group of from 1 to 22 carbon atoms; R₂ is an aliphatic grouphaving from 12 to 22 carbon atoms; R₃ and R₄ are each alkyl groups offrom 1 to 3 carbon atoms; and X is an anion selected from halogen,acetate, phosphate, nitrate and methyl sulfate radicals.

Because of their excellent softening efficacy and ready availability,preferred-cationic antistat/softener compounds of the invention are thedialkyl dimethyl ammonium chlorides, wherein the alkyl groups have from12 to 22 carbon atoms and are derived from long-chain fatty acids, suchas hydrogenated tallow. As employed herein, alkyl is intended asincluding unsaturated compounds such as are present in alkyl groupsderived from naturally occurring fatty oils. The term "tallow" refers tofatty alkyl groups derived from tallow fatty acids. Such fatty acidsgive rise to quaternary softener compounds wherein R₁ and R₂ havepredominantly from 16 to 18 carbon atoms. The term "coconut" refers tofatty acid groups from coconut oil fatty acids. The coconut-alkyl R₁ andR₂ groups have from about 8 to about 18 carbon atoms and predominate inC₁₂ to C₁₄ alkyl groups. Representative examples of quaternary softenersof the invention include tallow trimethyl ammonium chloride; ditallowdimethyl ammonium chloride; ditallow dimethyl ammonium methyl sulfate;dihexadecyl dimethyl ammonium chloride; di(hydrogenated tallow) dimethylammonium chloride; dioctadecyl dimethyl ammonium chloride; dieicosyldimethyl ammonium chloride; didocosyl dimethyl ammonium chloride;di(hydrogenated tallow) dimethyl ammonium methyl sulfate; dihexadecyldiethyl ammonium chloride; dihexadecyl dimethyl ammonium acetate;ditallow dipropyl ammonium phosphate; ditallow dimethyl ammoniumnitrate; di(coconut-alkyl) dimethyl ammonium chloride.

An especially preferred class of quaternary ammonium antistat/softenersof the invention correspond to the formula: ##STR11## wherein R₁ and R₂are each straight chain aliphatic groups of from 12 to 22 carbon atomsand X is halogen, e.g., chloride or methyl sulfate. Especially preferredare ditallow dimethyl ammonium chloride and di(hydrogenatedtallow-alkyl) dimethyl ammonium chloride and di(coconut-alkyl) dimethylammonium chloride, these compounds being preferred from the standpointof excellent softening properties and ready availability.

Nonionic fabric antistat/softener materials include a wide variety ofmaterials including sorbitan esters, fatty alcohols and theirderivatives and the like. One preferred type of nonionic fabricantistat/softener material comprises the esterified cyclic dehydrationproducts of sorbitol, i.e., sorbitan ester. Soritol, itself prepared bycatalytic hydrogenation of glucose, can be dehydrated in well-knownfashion to form mixtures of cyclic 1,4- and 1,5-sorbitol anhydrides andsmall amounts of isosorbibes. (See Brown; U.S. Pat. No. 2,322,821;issued June 29, 1943). The resulting complex mixtures of cyclicanhydrides of sorbitol are collectively referred to herein as"sorbitan". It will be recognized that this "sorbitan" mixture will alsocontain some free uncyclized sorbitol.

Sorbitan ester fabric antistat/softener materials useful herein areprepared by esterifying the "sorbitan" mixture with a fatty acyl groupin standard fashion, e.g., by reaction with a fatty (C₁₀ -C₂₄) acid orfatty acid halide. The esterification reaction can occur at any of theavailable hydroxyl groups, and various mono-, di-, etc., esters can beprepared. In fact, complex mixtures of mon-, di-, tri-, and tetra-estersalmost always result from such reactions, and the stoichiometric ratiosof the reactants can simply be adjusted to favor the desired reactionproduct.

The foregoing complex mixtures of esterified cyclic dehydration productsof sorbitol (and small amounts of esterified soribtol) are collectivelyreferred to herein as "sorbitan esters". Sorbitan mono- and di-esters oflauric, myristic, palmitic, stearic and behenic acids are particularlyuseful herein for conditioning the fabrics being treated. Mixed sorbitanesters, e.g., mixtures of the foregoing esters, and mixtures prepared byesterifying sorbitan with fatty acid mixtures such as the mixed tallowand hydrogenated palm oil fatty acids, are useful herein and areeconomically attractive. Unsaturated C₁₀ -C₁₈ sorbitan esters, e.g.,sorbitan mono-oleate, usually are present in such mixtures. It is to berecognized that all sorbitan esters, and mixtures thereof, which areessentially water-insoluble and which have fatty hydrocarbyl "tails",are useful fabric antistat/softener materials in the context of thepresent invention.

The preferred alkyl sorbitan ester fabric antistat/softener materialsherein comprise sorbitan monolaurate, sorbitan monomyristate, sorbitanmonopalmitate, sorbitan monostearate, sorbitan monobehenate, sorbitandilaurate, sorbitan dimyristate, sorbitan dipalmitate, sorbitandistearate, sorbitan dibehenate, and mixtures thereof, the mixedcoconutalkyl sorbitan mono- and di-esters and the mixed tallowalkylsorbitan mono- and di-esters. The tri- and tetra-esters of sorbitan withlauric, myristic palmitic, stearic and behenic acids, and mixturesthereof, are also useful herein.

Another useful type of nonionic fabric antistat/softener materialencompasses the substantially water-insoluble compounds chemicallyclassified as fatty alcohols. Mono-ols, di-ols, and poly-ols having therequisite melting points and water-insolubility properties set forthabove are useful herein. Such alcohol-type fabric conditioning materialsalso include the mono- and di-fatty glycerides which contain at leastone "free" OH group.

All manner of water-insoluble, high melting alcohols (including mono-and di-gylcerides), are useful herein, inasmuch as all such materialsare fabric sustantive. Of course, it is desirable to use those materialswhich are colorless, so as not to alter the color of the fabrics beingtreated. Toxicologically acceptable materials which are safe for use incontact with skin should be chosen.

A preferred type of unesterified alcohol useful herein includes thehigher melting members of the so-called fatty alcohol class. Althoughonce limited to alcohols obtained from natural fats and oils, the term"fatty alcohols" has come to mean those alcohols which correspond to thealcohols obtainable from fats and oils, and all such alcohols can bemade by synthetic processes. Fatty alcohols prepared by the mildoxidation of petroleum products are useful herein.

Another type of material which can be classified as an alcohol and whichcan be employed as a fabric antistat/softener material in the instantinvention encompasses various esters of polyhydric alcohols. Such"ester-alcohol" materials which have a melting point within the rangerecited herein and which are substantially water-insoluble can beemployed herein when they contain at least one free hydroxyl group,i.e., when they can be classified chemically as alcohols.

The alcoholic di-esters of glycerol useful herein include both the1,3-di-glycerides and the 1,2-diglycerides. In particular, di-glyceridescontaining two C₈ -C₂₀, preferably C₁₀ -C₁₈, alkyl groups in themolecule are useful fabric conditioning agents.

Non-limiting examples of ester-alcohols useful herein include:glycerol-1,2-dilaurate; glycerol-1,3-dilaurate; glycerol-1,2-myristate;glycerol-1,3-dimyristate; glycerol-1,2-dipalmitate;glycerol-1,3-dipalmitate; glycerol-1,2-distearate andglycerol-1,3-distearate. Mixed glycerides available from mixedtallowalkyl fatty acids, i.e., 1,2-ditallowalkyl glycerol and1,3-ditallowalkyl glycerol, are economically attractive for use herein.The foregoing ester-alcohols are preferred for use herein due to theirready availability from natural fats and oils.

Mono- and di-ether alcohols, especially the C₁₀ -C₁₈ di-ether alcoholshaving at least one free --OH group, also fall within the definition ofalcohols useful as fabric antistat/softener materials herein. Theether-alcohols can be prepared by the classic Williamson ethersynthesis. As with the ester-alcohols, the reaction conditions arechosen such that at least one free, unetherified --OH group remains inthe molecule.

Ether-alcohols useful herein include glycerol-1,2-dilauryl ether;glycerol-1,3-distearyl ether; and butane tetra-ol-1,2,3-trioctanylether.

The fabric antistat/softeners mentioned above can be used alone or asmixtures in combination with the imidazolinium compound in the practiceof the present invention. The agents when present in the compositions ofthe present invention are normally present in amount ranging from about1 to 12% by weight of the composition, preferably from about 1 to about8%. Preferred mixtures are mixtures of the quaternary imidazolinium saltwith a sorbitan ester, a fatty alcohol, or a quaternary ammoniumcompound. A most preferred mixture is the quaternary imidazolinium saltwith ditallow dimethyl ammonium chloride (DTDMAC). These two compoundsare preferably used in a weight ratio of from about 80/20 to about 20/80and most preferably in a weight ratio of from 30/70 to 70/30imidazolinium/DTDMAC.

Conventional liquid fabric conditioning composition components may bedissolved or dispersed in the composition. These conventional componentsinclude clay materials, aldehyde preservatives, emulsifiers, thickeners,opacifiers, coloring agents, brighteners, fluorescers, pH adjustmentagents and perfume materials. Such optional materials generally compriseabout 0.01% to 10% by weight of the composition.

Processing

The aqueous fabric conditioning compositions herein can be prepared byadding the fabric softening and static control agents to water usingconventional techniques. For example, the agent or agents can be heatedto form a liquid oily phase and can be added with mixing to watermaintained at elevated temperatures. Optional ingredients can be addedaccording to methods known in the art. The composition is then adjustedto a pH of from about 3 to about 9, preferably from about 4.5 to 7.

Composition Usage

The compositions of the present invention are preferably used in therinse cycle of the conventional automatic laundry operations. Generally,rinse water has a temperature of from about 15° C. to about 60° C.

When compositions of the present invention are added to the rinse cycle,the fabric conditioning agents are generally present at levels of fromabout 2 ppm to about 500 ppm, preferably from about 10 ppm to about 100ppm. These concentration levels achieve superior fabric softening andstatic control.

In general, the invention herein in its fabric conditioning methodaspect comprises: (a) washing fabrics in a conventional automaticwashing machine with a detergent composition (normally containing adetersive surfactant or mixture of surfactants selected from the groupconsisting of anionic, nonionic, amphoteric or ampholytic surfactants),(b) rinsing the fabrics, and (c) adding during the rinse stage of theoperation the above-described levels of the fabric conditioning agents.Preferably, a final step (d) includes drying the fabrics in an automaticdryer at a temperature of at least about 38° C. This drying stagefacilitates spreading of the fabric conditioning materials herein acrossthe fabric surfaces and is especially useful when the particulatesorbitan ester material is utilized.

The following exemplifies the fabric conditioning compositions andmethods of this invention and the benefits achieved by the utilizationof such compositions and methods. These examples are illustrative of theinvention herein and are not necessarily considered as limiting thereof.

EXAMPLE I

An imidazolinium salt essentially free of amines, amine salts andpropoxylated imidazolinium salts is prepared in the following manner:

A. diethylenetriamine and hardened tallow triglyceride in a molar ratioof amine/triglyceride of approximately 1.4/1 are added to a reactionvessel.

B. the amine and triglyceride are reacted for a period of 3 hours at atemperature of approximately 185° C. and atmospheric pressure.

C. the pressure in the reaction vessel is reduced to approximately 10 mmmercury and kept at that condition for a period of two hours. Theproduct at this point is the imidazoline intermediate for the desiredimidazolinium salt plus unreactants and primary and seconary amines fromintermediate amide products. The reaction mixture is analyzed usingconventional analytical techniques for the amount of imidazoline andprimary and secondary amines.

D. the reaction vessel is cooled to 80° C. and isopropyl alcohol isadded to the vessel in an amount equal to approximately 20% of thevessel's contents. The solvent aids in keeping the reaction mediumfluid.

E. propylene oxide is added to the reaction vessel in an amount equal toapproximately 2% of the imidazoline and unreactants. This amount issufficient to convert the unreacted primary and secondary amines topropoxylate tertiary amine.

F. the reaction vessel is subjected to a vacuum of approximately 10 mmmercury for a period of 1 hour.

G. the propoxylated reaction mixture is finally charged with analkylating agent in the form of dimethylsulfate. The amount ofalkylating agent originally used is slightly less than the number ofmoles of imidazoline formed after step C above. As the alkylationproceeds the pH of the reaction medium is monitored and additionaldimethylsulfate is added until the pH is in the 5-7 range.

The product formed in the above reaction is1-methyl-1-tallowamidoethyl-2-tallow imidazolinium methylsulfate whichis essentially free of amines and amine salts.

EXAMPLE II

The following compositions are prepared:

    ______________________________________                                                    A           B                                                     ______________________________________                                        Imidazolinium salt of                                                                       26.25 grams   --                                                Example 1                                                                     Imidazolinium salt of                                                                       --            26.25 grams                                       Example I made without                                                        employing the propylene                                                       oxide step                                                                    Aldehyde source                                                                              0.55 grams    0.55 grams                                       Water         q.s. to 1000 grams                                                                          q.s. to 1000 grams                                ______________________________________                                    

The pH of both samples are adjusted to 5.8 with sodium hydroxide.

Compositions A and B are analyzed for remaining aldehyde after one weekat the temperatures shown below. The amount of aldehyde originally inthe compositions is 550 ppm.

    ______________________________________                                        Temperature     A           B                                                 ______________________________________                                         70° F   510 ppm     470 ppm                                           100° F   508         401                                               120° F   464         346                                               ______________________________________                                    

The above figures demonstrate the improved aldehyde stability with theimidazolinium essentially free of amines and amine salts. Similarresults are obtained with other imidazolinium salts made usingpolyamines and acylating or esterifying agents other than thediethylenetriamine and tallow triglyceride of Example I.

What is claimed is:
 1. A fabric conditioning composition comprising aquaternary imidazolinium salt of the following structure: ##STR12##wherein R and R₁ are aliphatic or cycloaliphatic hydrocarbon groupshaving from about 10 to about 22 carbon atoms, R₂ is an alkyl,substituted alkyl or aralkyl having from 1 to about 8 carbon atoms, R₃and R₄ are hydrogen, hydroxy, short chain alkyl having from 1 to about 4carbon atoms or hydroxy short chain alkyl having from 1 to about 4carbon atoms, D is ##STR13## wherein n is a number from 1 to about 6,and X is an anion; said composition containing a total less than about4% of primary amines, secondary amines and cyclic tertiary amine saltsbased on the weight of the imidazolinium salt and less than about 25% ofan alkoxylated form of the imidazolinium salt based on the weight ofsaid salt.
 2. The composition of claim 1 wherein the composition is inaqueous liquid form and the imidazolinium salt is present at a level offrom about 1 to about 15% by weight.
 3. The composition of claim 2wherein R and R₁ are aliphatic or cycloaliphatic hydrocarbon groupshaving from about 14 to 20 carbon atoms.
 4. The composition of claim 3wherein R₃ and R₄ are hydrogen.
 5. The composition of claim 4 wherein Rand R₁ are derived from tallow fatty acid.
 6. The composition of claim 5wherein R₂ is methyl and X is methylsulfate.
 7. The composition of claim6 wherein D is ##STR14## The concentration of the imidazolinium salt isfrom about 2 to about 8% by weight and the pH of the composition is fromabout 4.5 to
 7. 8. The composition of claim 2 wherein the concentrationof the imidazolinium salt is from 2 to about 8% by weight and thecomposition additionally contains another organic fabric conditioningagent which is free of primary amines, secondary amines, and cyclictertiary amine salts in an amount equal to from about 1 to about 12% byweight.
 9. The composition of claim 8 wherein the additional fabricconditioning agent is selected from the group consisting of fattynonionic and cationic materials.
 10. The composition of claim 9 whereinthe additional fabric conditioning agent is selected from the groupconsisting of quaternary ammonium compounds, fatty alcohols and sorbitanesters.
 11. The composition of claim 10 wherein on the imidazoliniumsalt D is ##STR15## R₁ and R₂ contain from 14 to 20 carbon atoms and R₃and R₄ are hydrogen.
 12. The composition of claim 11 wherein on theimidazolinium salt R and R₁ are tallow, R₂ is methyl and X ismethylsulfate.
 13. The composition of claim 12 wherein the additionalfabric conditioning agent is dimethyl ditallow ammonium chloride and theweight ratio of imidazolinium salt to dimethyl ditallow ammoniumchloride is from about 20/80 to about 80/20.
 14. A method forconditioning fabrics comprising the steps:(a) washing fabrics in anaqueous detergent bath containing a detergent; (b) rinsing the fabricsin an aqueous rinse bath; (c) adding to said rinse bath from about 2 ppmto about 500 ppm of a fabric conditioning agent having the structure##STR16## wherein R and R₁ are aliphatic or cycloaliphatic hydrocarbongroups having from about 10 to about 22 carbon atoms, R₂ is an alkyl,substituted alkyl or aralkyl having from 1 to about 8 carbon atoms, R₃and R₄ are hydrogen, hydroxy, short chain alkyl having from 1 to about 4carbon atoms or hydroxy short chain alkyl having from 1 to about 4carbon atoms, D is ##STR17## wherein n is a number from 1 to about 6,and X is an anion; said imidazolinium salt containing a total less thanabout 4% of primary amines, secondary amines and cyclic tertiary aminesalts; (d) drying said fabrics.
 15. The method of claim 14 wherein R andR₁ are aliphatic or cycloaliphatic hydrocarbon groups having from about14 to about 20 carbon atoms and R₃ and R₄ are hydrogen.
 16. The methodof claim 15 wherein R₂ is methyl, X is methylsulfate and R and R₁ aretallow.